1. Technical Field
This invention relates generally to fuel injected internal combustion engines and more particularly to structures within the combustion chamber of such engines through which fuel injected is transported to respective desired locations within the combustion chamber.
2. Background Art
Widespread concern for protection of the environment has led to increasingly stringent limitations on harmful emissions from internal combustion engines. Carefully timed and precisely metered injection of fuel directly into the combustion chambers of internal combustion engines has proven to be one method of reducing undesirable combustion product emissions. Traditional efforts have been directed to improving the mixing of fuel and air within the combustion chamber prior to combustion. For example, various shapes, such as wedge, hemispherical, elliptical, or toroidal, depressions in the piston crown, and pre-chamber, scroll, and other cylinder structures have been proposed to increase the homogeneity and dispersion of the fuel/air mixtures within the combustion chamber prior to combustion.
Heretofore, fuel/air mixing improvements have been directed to increased mixing and flow control of the mixture. For example, U.S. Pat. No. 2,269,084 granted on Jan. 6, 1942 to J. J. McCarthy for an Internal Combustion Engine describes the use of arcuate ribs and baffles on the piston crown that cooperate to direct intake air drawn into the combustion chamber during the intake stroke into a vortex that is formed into a rapidly whirling air column that achieves its greatest turbulence just before fuel is injected into the combustion chamber. In a similar manner, U.S. Pat. No. 4,617,888 granted Oct. 21, 1986 to John C. Dent for a Piston for Internal Combustion Engines, proposes the use of arcuate ribs extending above the piston crown to provide turbulence in the fuel/air mixture prior to combustion and prevent the combustion flame front from spreading straight across the top of the piston without being deflected by one of the ribs. More recently, U.S. Patent Publication No. US2007/0044755A1 published Mar. 1, 2007 for a Device and Method to Increase Fuel Burn Efficiency in Internal Combustion Engines by Harry V. Lehmann proposes the use of vanes extending outwardly from the top of the piston to induce vortexes in the fuel/air mixture prior to combustion.
Notwithstanding all previous attempts to improve combustion fuel/air mixing, further improvements are needed to achieve lower engine emissions and better fuel economy. None of the aforementioned proposals are directed to better placement and distribution of the injected fuel within the combustion chamber prior to mixing with the intake air charge. The present invention is directed to overcoming the problem of less than ideal distribution of fuel in the combustion chamber prior to mixing with air and subsequent combustion. In accordance with the present invention, improved placement and distribution of fuel within the combustion chamber is achieved by transporting portions of the fuel, after discharge from a fuel injector, to optimally preferred areas of the combustion chamber before being introduced into, and mixed with, intake air.